AGY Introduces Ultra-Fine Yarns for PCB Substrates

April 13th, 2010 by

AIKEN, SC, USA – (April 13, 2010) – AGY, a leading global producer of glass fiber
yarns and high-strength glass fiber reinforcements, recently announced the introduction of
ultra-fine yarns for use in printed circuit board (PCB) substrates. Designed to meet the
growing needs of the electronics market where miniaturization and increased functionality are
expanding exponentially, these ultra-fine yarns allow PCB suppliers to create thinner
laminates for higher layer counts and greater circuit density.

“As electronic devices become smaller and include more functions, the complexity of
PCB design continues to expand,” explained Scott Northrup, Director of New Business
Development at AGY. “This means adding more conducting layers in the same thickness of
board. In order to accomplish this, glass fabric reinforcement must become even thinner and
this requires finer and finer glass yarns.”

AGY’s new ultra-fine yarns are on the cutting edge of glass fiber yarn development.
“What makes them ultra-fine is the small number of fine diameter filaments comprising the
yarn,” said Northrup. “For example, our C1200 yarn, which is used to produce fabric style
1037, consists of 100 filaments of 4.5 micron diameter. Our BC 1500 yarn, used to produce
fabric style 1027, consists of 100 filaments of 4 micron diameter. Our BC 3000 yarn,
currently under development, will contain only 50 filaments of 4 micron diameter. For
comparison, until the introduction of ultra-fine yarns, the finest yarns for PCBs have been 5
micron, typically with 100 or 200 filaments – known as D900 and D450. Other common
yarns used in PCBs consist of 200 or 400 filaments of 7 or 9 micron diameter.”

Used as a reinforcement and dielectric, the ultra-fine yarn is woven into fabric and
then laminated with epoxy resin and copper foil to produce copper clad laminate – the building
block of PCBs. “The yarn’s E-Glass composition makes it an excellent electrical insulator and
provides thermo-mechanical stability to the PCBs,” said Northrup. “Reinforcement with glass
fiber fabrics results in excellent dimensional stability which means the board will not warp
and twist under stress and heat.”

Ultra-fine yarn is particularly well suited for rigid-flex PCBs. This new technology
has emerged to meet the ever-increasing need to maximize available space within the
electronic assembly. “It allows designers to “fit the circuitry to the device” rather than fit the
device to the circuitry,” explained Northrup. “The fine diameter of our ultra-fine yarns is
conducive to very thin circuits that may involve some degree of flexing or bending. Another
emerging market for ultra-fine yarn is mobile communications base stations that require very
high layer count boards and a high degree of functionality in a given space.”

AGY has been a major supplier of fine yarns to the PCB sector for decades and is a
recognized leader in the quality and breadth of its product line. Adding ultra-fine yarns to its
portfolio is an achievement forAGY’s technology team explained Northrup, “The finer the
glass filaments, the more difficult they are to produce. AGY’s new ultra-fine yarns will
enable the continued development of more sophisticated electronic devices such as
smartphones to satisfy the demand for smaller and faster products that deliver more features
and functionality.”